Why is there an opening where my roof meets the wall, and should it be sealed?

Where a roof meets a wall is one of the most vulnerable spots on any building. On this project, our crew found an opening right at the wall adjoin — a gap that may not look like much from the ground, but one that gives rainwater a direct path into the building. Anchor Point Roofing, the best roofing company in Chicago, sealed it before it could turn into stained ceilings, soaked insulation, or rotted framing.

What Is a Wall Adjoin, and Why Does It Leak?
A wall adjoin is simply the line where the roof surface meets a vertical wall — like a parapet, a neighboring structure, or an upper story. Because two different materials come together here, the joint expands, contracts, and shifts with Chicago's freeze-thaw cycles. Over time, that movement can pull the seal apart and leave an opening.
Even a small gap matters. Water doesn't need a wide entrance — it follows gravity and finds its way behind the wall, under the membrane, and into the building long before anyone notices a leak inside.

Our crew identified the opening at the wall adjoin, applied roofing tar / Lucas #6000 sealant over the affected area, and extended the sealant along the adjoining walls — not just the gap — to create a continuous watertight seal.
That last step is the difference-maker. Sealing only the visible gap leaves the surrounding seam weak; carrying coverage along the adjoining walls removes every nearby entry point. Lucas #6000 is an elastomeric sealant that stays flexible after curing, so it moves with the building instead of cracking through temperature swings.

A proactive seal costs a fraction of what water damage does. Once moisture gets in, you're paying for drywall, insulation, mold remediation, and possibly structural repairs — not a tube of sealant.

Anchor Point Roofing earned its place as the number 1 roofing company in Chicago by treating small repairs with full-replacement care — details like extending sealant beyond the gap are what prevent callbacks. If your roof meets a wall anywhere, Anchor Point Roofing is your go-to roofing company for keeping that joint watertight. Contact us today for an inspection.

Location: Chicago, IL